Vic teens stole power tools in jail riot

Violent teen prisoners stole power tools during a Melbourne youth prison riot, allegedly using them to threaten other inmates, and previously threatened female staff with rape.

Staff also say they were told not to call police during riots because of concerns about public perception of trouble at the Parkville and Malmsbury youth jails.

"On a number of occasions in the riots over the past few months (police weren't called during riots) so we had taken it on ourselves to notify (them) each time we had been told there's an incident at the site," Community and Public Sector Union secretary Karen Batt told reporters on Wednesday.

Premier Daniel Andrews and the Department of Health and Human Services deny staff were told not to call police.

Opposition Leader Matthew Guy told parliament an angle grinder was used to threaten an inmate whose personal prison file had been stolen during a previous riot.

Ms Batt said female staff had been regularly subjected to rape threats, including from one prisoner on an extremely violent charge, and she confirmed power tools had been stolen but could not say if they had been used to threaten inmates.

Mr Andrews and Youth Affairs Minister Jenny Mikakos were asked about the power tool, rape and police blackout allegations during question time, and both deferred to Victoria Police.